Revealing mistake: When the water tank falls over, the vapour fumes are moving in slo-mo, despite the whole scene moving at a normal speed.
Continuity mistake: When the three heroes arrive at the village there's not a single bit of grass around. When they leave the place the morning after there's vegetation everywhere.
Continuity mistake: During the fight on the conveyor belt in the mine, the buckets and huge rock used to defeat the bearded giant keep changing positions all the time.
Continuity mistake: Indy's raft lands on the water, and he is ducking but rises up and rows with his hands for a couple of seconds. Then a frame later he is still ducking and rises up again.
Revealing mistake: When Willie and Short escape the jet of water and Indy climbs the mountain alone, the river below is totally still (impossible because of the huge amount of water that's falling on it), revealing it's a still image.
Continuity mistake: When Mola Ram is climbing the bridge, Willie and Short stand together; half a second later Mola Ram falls and Short has managed to climb up and move apart to let him pass by. Then a nano-second later, Mola Ram grabs onto a piece a wood and Short and Willie manage to stand together again. (01:41:15)
Continuity mistake: On the bridge, an arrow suddenly appears to the right of Indy's foot seconds before any arrows are shot at him. (01:42:55)
Chosen answer: His neck was snapped by the whip getting caught in the fan. There isn't always blood with a hanging. Since the fan wasn't designed to hold a man's weight, the motor in it would have stopped or given out.
Captain Defenestrator